1. Related Inventions
______________________________________ TITLE Ser. No. FILING DATE U.S. Pat. No. ______________________________________ Inverted Cap For 07/888,552 May 22, 1992 5,263,787 Craft Paint Applicators Self Adjusting 07/888,059 May 22, 1992 5,340,228 Soft Seal Cap For Fine Point Craft Paint Applicators Craft Paint For 07/887,699 May 22, 1992 abandoned Forming High Resolution Designs Craft Paint 07/887,289 May 22, 1992 5,209,663 System For Forming Fine Designs and Method Therefor ______________________________________
2. Field of the Invention
The present invention relates to the field of applying craft paint and, more particularly, to the field of using fine point, easy flow applicator tips for craft paint to form painted designs with a finely detailed, color dot matrix having a high degree of resolution and color saturation.
3. Statement of the Problem
There is great interest in forming stylized decorative designs on surfaces, such as fabrics, wood, leather, painted surfaces, and vinyl surfaces as well as other surfaces, through the use of craft paints. Craft paints are widely used since a colorful design can be quickly created on a variety of surfaces. In craft painting, the design is not usually limited to a pattern since normally the design is painted quickly in a free hand style. The free hand style design can thus be creative and colorful. Alternatively, craft painting can be applied by the use of patterns to create a particular design.
One novel application of craft paint, set forth in the above related inventions, is the creation of stylized decorative designs on a surface by applying uniform three dimensional discrete beads closely spaced together to form a color dot matrix pattern that visually merges together to form a solid line or field of color having a high degree of resolution and color saturation. One such design is illustrated in FIG. 1. The design is created on a fabric surface 2 by a plurality of beads 6 of differing colors. Each of the beads 6 have a uniform homogenous shape, as shown in FIG. 2 to provide a dimensional, textured appearance. The term "uniform" as used herein refers to beads having a regular size and a smooth substantially rounded spherical shape. A fine tip, easy flow applicator tip having an outside diameter at the dispensing end of less than about 0.060 inches and a sidewall thickness of less than about 0.015 inches is required in order to create the beads 6 shown in FIG. 2.
Conventionally, craft paints are provided in applicators having either tubular or conically-shaped tips. The craft paint is applied directly on the application surface from the applicator through these applicator tips. Such conventional applicators are suitable for free style designs, but are not suitable for fine detail work, especially involving the application of discrete beads necessary for dimensional textured appearances as shown in FIGS. 1 and 2.
Conventional tubular applicator tips are used in situations requiring a finely detailed application. Tubular tips normally have a cylindrically shaped tip with an outside diameter greater than 0.080 inches and sidewall thicknesses greater than 0.025 inches and a relatively long length to provide a line of sight for the user to create patterned designs. Tubular tips provide an improved line of sight application but have other drawbacks. The small inner diameter coupled with the length of the tubular tip results in a long narrow inner passage and, therefore, creates a problem with the flow resistance of the paint flow.
Flow resistance is caused by the shear forces of the paint flow in a long, small diameter passageway. The flow resistance causes several problems with the application of craft paint. A first problem is the hand fatigue of the user in forcing the paint against the flow resistance. Greater forces are necessary to overcome the flow resistance against the paint. The narrower the passageway and/or the longer the passageway, the greater the force. This increased force requires greater hand pressure against the applicator by the user which leads to hand fatigue. This detracts from the enjoyment of creating the stylized design. A second problem is the greater susceptibility to clogging within the applicator tip. If the paint partially dries within the applicator tip or if impurities or other objects in the paint occur, the flow resistance is increased even more since there is no room available for the paint to flow around any blockage. A third problem arising from the flow resistance occurs in the rheology of the paint. The flow characteristics of the craft paint changes as the shear forces in the paint flow increase. Increases in the shear forces cause the paint to become thinner, i.e. the paint viscosity is lowered. The change in viscosity changes the character of the paint. For instance, thinner paint will not form beads as well as thicker paint, nor will the application of the paint be as uniform. These are critical factors in the application of craft paint in uniform discrete three-dimensional beads as necessary for creating finely detailed structured designs.
Conventional conically-shaped tips minimize these effects caused by shear forces on the paint flow. Since the inner passage- way of a conically-shaped applicator tip only narrows down at the dispensing end of the applicator tip, the shear forces are much smaller and the flow resistance is lowered. Thus, the problems with hand fatigue and changes in the craft paint rheology are not major factors with the conically-shaped applicator tips when compared with tubular tips. However, conically shaped tips are not suitable for use with finely detailed designs. These applicators are designed to apply craft paint in a continuous linear fashion, such as stripes, not in discrete beads. The size and shape of the tips make it difficult to precisely position the tip and to apply small, discrete beads of craft paint in a uniform fashion to form a detailed pattern. The paint flow within the conically-shaped tips is often turbulent which causes spattering or lack of control of the paint or, to the application surface. This disrupts the creation of a finely detailed pattern.
Also, the conical shape of conventional craft paint applicator tips have thick sidewalls and provide inner surface areas for the craft paint to accumulate and dry, thus clogging the tips. The orifice size of the prior applicators typically must be of a relatively large diameter due to this clogging problem which permits more air into the passageway. As a result, the craft paint is applied in relatively large amounts through these orifices. The sizes of the orifices also are altered as the craft paint dries around and within the orifices. Hence, conically shaped applicator tips are not designed for fine-point work.
Many prior art applicator tips are affixed on the applicator by snapping or threading the applicator tips onto the applicator bottle, normally during the manufacturing process. These tips are usually not removable without considerable effort and with the possibility of damaging the tip. If these tips become clogged, as frequently occurs, the tips must be re-punctured with a sharp object which can affect the diameter of the tip orifice. If the prior tips become too damaged, then the entire applicator bottle and remaining paint may be rendered useless. Also, and more importantly, the clogging obstruction is pushed back into the bottle and may resurface later to again clog the tip.
It is clear that the aforesaid problems do not generally affect or interfere with the conventional free-style application of craft paint onto surfaces. However, when used for detailed designs especially the creation of discrete beads of craft paint for dimensional textured appearances as shown in FIGS. 1 and 2, all of the aforesaid problems arise and become critical to creating a desired design. Thus, a problem exists in that, at present, there is no craft paint applicator tip having an outside diameter at the dispensing end of less than about 0.060 inches with a sidewall thickness of about less than 0.015 inches. Such a tip provides a fine, consistent laminar flow for detailed designs such as application of discrete beads of craft paint for fine, dimensional appearances.
4. Solution to the Problem
The present invention solves this problem and others by providing a craft paint applicator tip that provides a fine, consistent laminar flow with reduced shear and one that is easily replaceable and cleanable.
The present invention includes an applicator tip having an inner parabolic shape with a smooth, clean finish to the interior sidewalls in order to provide laminar flow with reduced shear so as to provide easy flow for the craft paint.
The applicator tip of the present invention has a inner orifice shape to substantially eliminate air bubbles, air turbulence and drying of the craft paint within the tip.
The applicator tip of the present invention provides a small diameter dispensing orifice less than about 0.060 inches in outside diameter, with sidewalls in the range of about 0.005 to 0.015 inches to produce finely sized, uniformly shaped discrete beads of craft paint onto a desired surface.
The applicator tip of the present invention is designed not to be susceptible to clogging of the dispensing orifice of the applicator tip.
The applicator tip of the present invention provides a smooth laminar flow of craft paint with reduced shear to consistently form uniformly shaped beads with minimum pressure on the applicator by the user.
The applicator tip of the present invention is easily removable for cleaning or replacement purposes.
The applicator tip of the present invention includes a shape and size to enhance the line of sight of the application of the craft paint in discrete beads to form a pattern having a dimensional appearance on the desired surface.
These and other features of the present invention will be evident in the ensuing drawings and description.